RasPi Check

Show the user the current system status of a running Raspberry Pi computer. To
gather the information needed, RasPi Check uses a SSH connection.

RasPi Check shows you overclocking information (frequency, temperature, volts)
and more system information (free memory, runtime, disk status). You can also
restart or halt your Raspberry Pi ® and send custom commands! If you always want
to keep an eye on your Pi there's also a widget for your homescreen.

All you need for the app to work are your SSH login credentials. You can either
authentificate via password or via private/public key.